Enhanced Conversions for Google Ads

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Estimated 9 mins

Prereq

Intermediate

Basic ML concepts helpful

Interactive

Static Playbook

Static guide & reference tables

What problem Enhanced Conversions actually solves

Third-party cookie restrictions, Safari's ITP, and ad blockers all erode Google's ability to match a conversion back to the ad click that drove it using click IDs (gclid) alone. Enhanced Conversions for Leads and Enhanced Conversions for Web both address this by sending Google first-party, hashed customer data — email, phone, name, address — alongside the conversion event, so Google can match conversions to ad interactions even when the click-ID-based signal is degraded or missing entirely.

Two distinct implementations, don't conflate them

Enhanced Conversions for Web augments conversions already being tracked via the Google Ads tag or GTM on your website — it hashes and sends available first-party customer data (collected at the point of conversion, like a checkout form) in addition to the existing conversion tag. Enhanced Conversions for Leads is for offline or CRM-based conversions — when a lead eventually becomes a sale days or weeks later in your CRM, you upload the hashed lead data via the Google Ads API or an offline conversion import, closing the loop between the original ad click and a conversion that happened far outside the browser session.

Google requires client-side hashing before transmission for web conversions

Enhanced Conversions for Web expects SHA-256 hashed values for email and phone (normalized first: lowercase, trimmed, phone in E.164 format) before they ever leave the browser. The Google Ads tag and the GTM Google Ads Conversion Tracking tag both support automatic hashing via a built-in 'User-provided data' field — you should let the tag do the hashing rather than hand-rolling it, since Google's exact normalization rules (removing dots from Gmail addresses, etc.) must match precisely for matches to succeed.

gtm_user_data_variable.js

typescript

// Custom JavaScript Variable feeding the GTM Google Ads tag's "User-Provided Data" field.
// Google's tag performs the SHA-256 hashing itself once this normalized object is passed in.
function() {
  var email = {{DLV - checkout_email}};
  var phone = {{DLV - checkout_phone}};
  return {
    "email": email ? email.trim().toLowerCase() : undefined,
    "phone_number": phone ? phone.replace(/[^\d+]/g, '') : undefined // E.164 format
  };
}

Server-side Enhanced Conversions

A server-side variant exists for teams running Google's server-side tagging: instead of hashing in the browser, you pass the raw first-party data server-side where it's hashed before the outbound call to Google. This keeps raw PII off the client and out of browser-based inspection entirely, and is the preferred pattern for any organization with a legal or security requirement against exposing even hashed PII client-side.

Enhanced Conversions for Web vs. for Leads

Dimension	Enhanced Conversions for Web	Enhanced Conversions for Leads
Conversion happens	On your website (purchase, signup)	Offline, later, usually in a CRM
Data source	Form fields at the point of conversion	CRM/sales record matched back to the original lead
Transport	Google Ads tag / GTM tag, client or server-side	Offline conversion import via API or bulk upload
Primary benefit	Recovers conversions lost to cookie/ITP degradation	Closes the loop on long sales cycles with no click-ID persistence

Match rate is not a guarantee — and consent still gates everything

Enhanced Conversions improves match rate, it doesn't create certainty. Google still probabilistically matches hashed data against its own signed-in user graph, and coverage varies significantly by vertical and whether users are signed into a Google account. It also requires that your consent setup (Consent Mode) permits ad personalization signals — if a user has declined ad consent, Enhanced Conversions data for that user should not be sent, regardless of technical capability to do so.

What's Next?

Enhanced Conversions is one half of closing the measurement gap; the other half — getting leads that convert offline back to Google Ads at all — depends on a correctly built offline conversion import pipeline, which has its own set of matching and timing considerations.

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